More on C++ stack arrays

[Adam D. Ruppe]

On Sunday, 20 October 2013 at 14:25:37 UTC, bearophile wrote:
> I'd like variable-sized stack-allocated arrays in D.

I think I would too, though it'd be pretty important, at least 
for @safe, to get scope working right.

Ideally, the stack allocated array would be a different type than 
a normal array, but offer the slice operator, perhaps on alias 
this, to give back a normal T[] in a scope storage class (the 
return value could only be used in a context where references 
cannot escape).

This way, the owner is clear and you won't be accidentally 
storing it somewhere.



An alternative to a stack allocated array would be one made from 
a thread-local region allocator, which returns a Unique!T or 
similar, which frees it when it goes out of scope. Such an 
allocator would be substantially similar to the system stack, 
fast to allocate and free, although probably not done in 
registers and perhaps not as likely to be in cpu cache. But that 
might not matter much anyway, I don't actually know.